Define most. Where I live it's standard to just walk around the locker room naked. No one cares. You just keep your eyes to yourself. The guys walking around with towels are the odd ones out. In Germany they often don't even have gender separated locker rooms. So most of what? The American population? Sure. Not all cultures are as timid about being nude. When I walk from my locker to the shower area I don't wear a towel, I walk naked carrying the towel in my hand simply because this is the easiest. While in the shower area I am, surprisingly, also nude. I then stand be the edge of the shower area drying myself with my towel. All the while being nude. Then I walk back to my locker, nude. Then, finally I put on underwear.
Why go through a huge hassle trying to keep yourself covered at all times just so you can avoid being seen naked by some other guys for 2min? You're just gonna look like some little adolescent kid who's afraid to show his body to his friends.

I didn't use the word penis one single time in the entire post. I talked about being naked and was making an example of how it didn't bother me. Apparently your own tenseness regarding nudity makes it impossible to see the word naked without instantly thinking of penis.